Coal Workers' Pneumoconiosis and Workers' Compensation - Schedule of Assumptions (Details)	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
CWP Benefits
Defined Benefit Plan Disclosure [Line Items]
Benefit obligations	5.57%	5.65%	5.14%
Net periodic benefit cost	5.65%	5.14%	5.40%
Workers’ Compensation
Defined Benefit Plan Disclosure [Line Items]
Benefit obligations	5.36%	5.58%	5.12%
Net periodic benefit cost	5.58%	5.12%	5.38%